Given the definition of the Country class: public class country { public enum Continent {ASIA, EUROPE} String name; Continent region; public Country (String na, Continent reg){ name = na, region = reg; } public String getName () {return name;} public Continent getRegion () {return region;} } and the code fragment: List<Country> couList = Arrays.asList ( new Country ("Japan", Country.Continent.ASIA), new Country ("Italy", Country.Continent.EUROPE), new Country ("Germany", Country.Continent.EUROPE)); Map<Country.Continent, List<String>> regionNames = couList.stream () .collect(Collectors.groupingBy (Country ::getRegion, Collectors.mapping(Country::getName, Collectors.toList())))); System.out.println(regionNames); 

Answer options:

A. {EUROPE = [Italy, Germany], ASIA = [Japan]}
B. {ASIA = [Japan], EUROPE = [Italy, Germany]}
C. {EUROPE = [Germany, Italy], ASIA = [Japan]}
D. {EUROPE = [Germany], EUROPE = [Italy], ASIA = [Japan]}

B